9.8 Boffin questions

Do ACE inhibitors increase susceptibility to COVID-19?

An angiotensin-converting enzyme, or ACE, is a central component of the renin–angiotensin system. This enzyme controls blood pressure by regulating the volume of fluids in the body. It converts the hormone angiotensin I to the active vasoconstrictor angiotensin II. People with hypertension are prescribed ACE inhibitors. These medications reduce blood pressure by encouraging the blood vessels to relax and open.

One side effect of ACE inhibitors, at least reported in animal models, is that they increase the expression of angiotensin-converting enzyme 2 (ACE2). SARS-CoV-2, the coronavirus which causes COVID-19, enters cells by binding a viral spike protein to ACE2. Therefore, there is concern that patients taking ACE inhibitors may be more susceptible to contracting COVID-19 and more susceptible to worse outcomes.

In the UK, COVID-19 infections were monitored by a COVID-19 symptom tracker app. The app allowed members of the public to contribute to research through self-reporting data including demographics, conditions, medications, symptoms and COVID-19 test results. Researchers observed that people reporting ACE inhibitor use were twice as likely to have a COVID-19 infection based on symptoms, even after adjusting for differences in age, body mass index, sex, diabetes and heart disease.

• Speculate on why this data could be misleading or incorrect.